The gospel is the joyful message from God that leads us to salvation.
God is our Creator. He is loving, holy, and just. One day He will execute perfect justice against all sin.
People are made in the image of God. We are beautiful and amazing creatures with dignity, worth, and value. But through our willful, sinful rebellion against God we have turned from being his children to his enemies. And yet, God, in love, calls all to be restored to relationship with him through faith.
Christ is the Son of God, whose sinless life gave him the ability to become the perfect sacrifice. Through his death on the cross, he ransomed sinful people. Christ's death paid for the sins of all who come to him in faith. Christ's resurrection from the dead is the ultimate vindication of the truth of these claims.
The response God requires from us is to acknowledge our sin, repent, and believe in Christ. So we turn from sin, especially the sin of unbelief, and turn to God in faith with the understanding that we will follow him the rest of our days.
(*Taken from Evangelism: How The Whole World Speaks of Jesus by J. Mack Stiles)